There are several forms of reset the simplest if the car takes it will be to tighten a couple of buttons that manages the boarding computer, but it depends on the manufacturer. . . Inform well. The second option is to make you with a laptop that has software such as: Autodata or Mitchell and Demand 5.8, I recommend this last since it is more complete (that you can get it in: W3.Gratisprograms.org, I know that this option seems complicated since apart from the portatil you will need an obd connector with USB (which is nothing more than a connected cable of the PC to the PC)
you have a friend who has a mechanical workshop and buy it for you.